@ Lu:
You would willingly switch off two hydraulic systems to stop the retracting flaps? Wow...
I'd think this would leave you with quite a bigger problem.
But even if you tried, how long would it take (in terms of time and number of buttons/levers to move) to really switch off both required HYD SYS? Wouldn't it be easier in this case to quickliy locate the WTB CBs and pull them? Ok, you'd have a frozen, non-resettable configuration. But it would be faster and you'd still have your HYD power for primary flight control.
Just a thought...